ST10F272M-4T3 STMicroelectronics, ST10F272M-4T3 Datasheet - Page 38

• Manufacturer Part Number: ST10F272M-4T3
• Description: MCU 16BIT 256K FLASH 144-LQFP
• Manufacturer: STMicroelectronics
• Series: ST10r

Specifications of ST10F272M-4T3

• Core Processor: ST10
• Core Size: 16-Bit
• Speed: 40MHz
• Connectivity: ASC, CAN, EBI/EMI, I²C, SSC, UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 111
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 20K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 24x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 144-MQFP, 144-PQFP
• Processor Series: ST10F27x
• Core: ST10
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

Internal Flash memory
5.5.7
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Access protection
The IFlash module has one level of access protection (access to data both in reading and
writing).
When bit ACCP of FNVAPR0 is programmed at 0 and bit TAUB in XFVTAUR0 is set at 0, the
IFlash module becomes access protected (data in the IFlash module can be read only if the
current execution is from the IFlash module itself).
Trying to read into the access protected Flash from internal RAM or external memories will
output a dummy data (software trap 009Bh).
When the Flash module is protected in access, data access through PEC transfers is also
forbidden. To read/write data through PEC in a protected bank, first it is necessary to
temporarily unprotect the Flash module.
To enable access protection, the following sequence of operations is recommended:
●
●
●
●
●
Protection can be permanently disabled by programming bit PDS0 of FNVAPR1H, in order
to analyze rejects. Protection can be permanently enabled again by programming bit PEN0
of FNVAPR1L. The action to disable and enable again access protections in a permanent
way can be executed a maximum of 16 times. To execute the above described operations,
the Flash has to be temporarily unprotected (see
Trying to write into the access protected Flash from internal RAM or external memories will
be unsuccessful. Trying to read into the access protected Flash from internal RAM or
external memories will output dummy data (software trap 0x009Bh).
When the Flash module is protected in access, data access through PEC of a peripheral is
also forbidden. To read/write data in PEC mode from/to a protected bank, it is necessary to
first temporarily unprotect the Flash module.
The following table summarizes all possible access protection levels: In particular, it shows
what is possible and not possible to do when fetching from a memory (see fetch location
column) supposing all possible access protections are enabled.
Table 24.
Fetching from IFlash
Fetching from IRAM
Fetching from XRAM
Fetching from external
memory
Fetch location
Execution from external memory or internal RAM
Program TAUB bit at 1 in XFVTAUR0 register
Program ACCP bit in FNVAPR0 to 0 using set protection operation
Program TAUB bit at 0 in XFVTAUR0 register
Access protection is active when both ACCP bit and TAUB bit are set to 0
Summary of access protection level
jump to IFlash
Read IFlash /
Yes/yes
No/yes
No/yes
No/yes
external memory/
jump to XRAM or
external memory
Read XRAM or
Yes/yes
Yes/yes
Yes/yes
Yes/yes
Section 5.5.9: Temporary
Read Flash
registers
Yes
No
No
No
unprotection).
Write Flash
ST10F272M
registers
No
No
No
No